<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        body{
            padding: 0;
            margin: 0;
            background: darkgrey;
        }
        .main{
            height: 100px;
            line-height: 100px;
            position: absolute;
            top :50%;
            left: 50%;
            transform: translate(-50%,-50%);
            font-size: 50px;
            letter-spacing: .2em;
           
        }
        .container{
            margin-right: 5px;
        }
        .delete{
            border-right: 2px solid black;
            /*step-end是动画过渡效果，设置step-end代表不过渡*/
            animation: blingbling 1s step-end infinite;
        }

        @keyframes blingbling{
            from,to{
                border-color: transparent;
            }
            50%{
                border-color: black;
            }
        }

    </style>
</head>
<body>
    <div class="main">
        <span class="container"></span><span class="delete"></span>
    </div>
    <script src="./index.js"></script>
</body>
</html>